Sealing means



Nov. 10, 1942. Y U 1 2,301,654 SEALING MEANS FiledApril so, 1940 \3 v 6a is //I/ ENTOR FF 5 R o ertBYauch r ma acrw Patented Nov. 10, 1942SEALING MEANS Robert B. Yauch, Battle Creek. Mlcln, ascignor of glfityhper cent to Elmer P. Harlow, Battle Creek,

Application April 30, 1940, Serial No. 332,563

1 Claim.

The present invention relates broadly to sealing mechanisms, and in itsspecific phasesto seals for use in connection with rotating shafts.

The sealing of rotating shafts has been a matter which has caused agreat deal of dimculty, the attempted solution of which has given risento the use of highly complex sealing mechanisms. One of the best knownseals involves the use of a conventional stufllng box-with packing, anda gland for compressing same. This type of seal is unsatisfactory formany purposes, and especially so where the rotating shaft is eitherscored, out of round, or gyrates. Packing of this nature, as well asmany others such as the spring held cup leather type, when installed incentrifugal pumps used for submerged pumping of muddy or grit carryingwater, commonly wears out in a single day's operation with resultantleakage, scoring of the shaft, and wearing of the pump parts due to thescouring action of the abrasives carried by the leaking fluid.

Inan attempt to overcome leakage due to gyration, seals of the bellowstype have been pro duced. The rotational strains, as well as the flexingof the frail bellows are well recognized as being common causes offailure of this type of seal. Rotating seals involving the use of aspring projected rubber gasket have also been used with little bettersuccess than the bellows type seals even where gyration difficulties arenot present. -A careful consideration of these and other difll cultiesin the rotating shaft sealing art lead to the development of the presentinvention which is widely useable and meets a long felt want in thisfield.

Accordingly, among the objects of the present invention is the provisionof a fluid sealing device for rotating shafts which effectivelyovercomes the above noted, objections to-seals or packings heretoforeused or proposed.

Another object is to provide a simplified, posi-- tive acting; sealingmechanism which forms a tight seal with the shaft, even under conditionsof moderate gyratlon of same.

A further object is to provide a seal which eliminates the use ofbellows, springs, and stufnng boxes with the failure difilcultlesincident thereto. n

A still further object is to provide a fluid sealing device for rotatingshafts which can be manufactured at relatvely low cost, is easy toinstall, and which is not subject to excessive wear due to improperbearing surfaces or unnecessarily heavy frictional contacts.

present invention will be apparent as the description of the inventionproceeds.

To the accomplishment of the foregoing and related ends, the invention,then, consists of the means hereinafter fully described and particularly pointed out in the claim, the annexed drawing and thefollowing description setting forth in detail certain means for carryingout the such disclosed means illustrating,

invention, however, but several of various ways in which the principleof the invention may be used.

In said annexed drawing:

Figure 1 shows a fragmentary center sectional view of a centrifugal pumpembodying one form of the present invention.

Figure 2 shows a fragmentary center sectional view of a centrifugal pumpembodying a modlfied form of the present invention.

Figure 3 is a perspective view of a notched end sleeve forming apreferre part of the assembly shown in Figure 1.

Figure 4 shows a perspective ".view of a washer with lugs adapted to fitthe notches in the end I of the sleeve shown in Figure 3.

Figure 5 is a sectional assembly view of a modified form of the sealingmechanism of the present invention. 1

Figure 6 is an end view of the mechani shown ln Figure 5 as viewed inthe direction of the arrows 6-8.

Figure '7 is an end view of the mechanism shown in Figure 5 as viewed inthe direction of the arrows 'l--l.

Referring more particularly to Figure 1 of the drawing, the centrifugalpump I has a casing 2, only a portion of which is shown, a shaft 3. andan impeller 4 with blades 5. The shaft I is mounted on suitable bearingsB, only one of which is shown. This bearing 8 within casing 2 acts bothto carry radial loads, and. endwise thrust loads, thus stabilizing shaft3 in an endwise direction and facilitating the operation of the improvedsealing mechanism hereinafter set forth in detail. End plate I anchoredby means of cap screws 8 to the end of casing I acts to protect bearingi from injury due to contact with large pieces of foreign matter. Tofurther facilitate this action, a sealing ring 9, formed of cup leathermaterial or other suitable packing may be placed in groove ll cut in theface of and closely In order to prevent fluid flow through the pumpalong shaft 3, a sealing mechanism is pro- Btill further objects andadvantages of the vided. One convenient form of this sealingcombination, as shown in Figure I, involves the use oi a tubular sleeveI! which is press fit into casing 2 of the pump. Mounted on this sleeve,for instance in a recess 13 to shorten the distance between bearing 6and impeller 4, is a tubular resilient bushing H of rubber or syntheticmaterial such as "neoprene" preferably in cylindrical form. The termneoprene" is typi---- cal of synthetic rubber of the "polymerizedchloroprene" type, and for simplicity of describing this tough and oilresistant resilient. material, it will be referred to in the claims assyn- 'thetic rubber." The particular type of resilient material used inthe bushing will depend in a large measure upon the conditions of use,the fluid to be pumped, and whether grease or oil is present. Forinstance, if the pump is to he used for pump gasoline, or bearing 8 ispacked full 01 greaseso that it may pass down the face of shaft 3 andreach bushing ",then this bushinzwill be formed from a grease oroilimpervious resilient material similar to rubber. Mounted to be highlyfinished, and in fact, a slight roughsecrete than the outer diameter ofsleeve i2 s o as to permit free oscillatory movement of same underconditions oi motion of shaft 3.

The use of sleeve it as such may be eliminated as shownin Figure 2 byextending casing 2a closer to shaft 311 and then boring recess i341 sothat it is in the form of a groove opening only at its outer end. Thisconstruction produces a sleeve-like projection is which takes the placeof the press fltisleeve l2 shown in Figure l. The outer end of,vsleeve-likeprojection i9 may be provided with notches as described inconnection with sleeve it, and washer lea may also he provided withinwardly projecting lugs as shown in Figure 4 so as to interengage withthe notches in projection. la. The showing in Figures 1 and 2 isintended'to diagrammatically illustrate constructions either with orwithout said notches and lugs. To provide better sealing action, the endof recess "a may be provided with a pin-- rality 0t corrugations 20, andthe inner face oi washer lia may likewise be provided with a on the endof sleeve I! in contact with the outer .-,'end oi bushing H is a washerl5, preferably made do! oilless bronze. The face of this washer incontact with the end of bushing It does not need 1 plurality ofcorrugations 2!. The use of washer '06 may be eliminated if desired, anda satisfactory way of accomplishing this is to term the impeller (Figure2) of steel or a copper-nickel cast iron. The face of this impelleradjacent washer lia, under these conditions, willlce given a ground orpolished finish adapted to contact directly with the correspondingflitfieifli washer its to form a tight seal therewith. .Case harden mgand heat treating oi the impeller do may also he resorted to in order toprovide a more Ii under conditions of rotation of the impeller;

'. The length 01' cylindrical bushing I4 is prefer ably such that it issufliciently longer before without the pressure being excessive to theear a lengthwisecompression of samein the range of one sixteenth tooneeighth inch is satisfactory for most p rposea aealine pressures up toeight or, nine'pounds per square inch are satisfactory forordinarycentrifugal pump use, A although the invention is not limited totheuse" of those specific pressures;

. emcient and wear resisting face in contact with washer lee.Suchprocedure has the further advantage of making the impeller as awhole satisfactorily wear longer under conditions or pumping muddyfluids, sandy fluids, or'the like.

installation, that the amount'of'compression of same when installed willtorcewasher it against the face otwasher l6; and forms tight seal 'Whilewashers to and it, or the equivalent may will? constructed with smoothlyrounded edges, a hotter construction involves the use of square J outsharp edges since such make more dimeuit v the entrance of foreignmatter between the contacting races of Washers it and it. The outerdiameter of these two washers is also preferably the same so as-to avoidthe presence of shoulalert at their junction which would he of aid toThe frictional component between the end of v bushing 14 and the side ofwasher is will one the latter against rotation under normal conditionsso that a rotary seal will take place at the adjacent faces of washersi5 and i6. However, where the pump is to be used in cold weather forpumping water, and the like, freezing oi.

water or moisture'in the pump may temporarily fasten washers i5 and 56together so'that they will tend to run as a unit with consequent wear 1on the end of bushing it. To avoid ditllculties oi this nature, sleeve52 may he provided with notches "'(Fisure 3) on its outer and, use

.washer I! may he provided with mwardly 'pro jecting lugs 18 (Figure 1)adapted to loosely iit notches I! under normal conditions of operation.- This type of construction provides for positive operation, and atthe some time facilitates the maintaining of a tight seal even whenshaft 3, under conditions of operation, gyrates slightly. It should benoted at this point that the inner bore of washer i5 is slightly largertween.

' to avoid or least reduce gyration dimculties,

the ingress oi foreign. abrasive matter therebe- Where it is deeldeol toplace the impeller oi a or where it is decided to seal the crank case ofa compressor against leakage of fluid along the crank shaft, a modifiedform of the present invention may be utilized. A conventionalconstruction of this nature is shown in Figure 5 wherein the wall 22 ofa pump casing, crank case, or the like is shown as equipped with a sealmechanism adapted to prevent leakage along shaft to which rotatablypasses tin-cosh a suitable tuhular member 23 mounted in openmg fi l ofwall 22. Tubular member 23 which may se ve either as an outlet membervor a hearing for shaft to may he coustructeolin various ways, end

one of the simplest involves the constriction of tubular member with aflange edge 25, one face of which is adapted to contact and grip asuitable washer lilre easiest 26 against the side of wall 22. Forconvenience of anchoring the tubular member 23 to wall 82, it may heprovided with external threads 2? on which a nut 2&3 and lock nut 2d areadapted'to threadedly fit. In this construction, the tightening of nut28 will clamp gasket is between well 22 and the adiacent face of flange2! of tubular member II, and thus produce a sealed joint with nut 28tightened in place. The tightening of lock nut I! will fasten tubularmember 23 against accidental disengagement. Where the present sealingmechanism is utilized, tubular member 23 is preferably made of oillessbronze, and its outer end ness of the rotary contact surface whichpreferably fits substantially perfectly throughout,

varies with the tightening of screws ll. Thus with a diflicult to holdfluid, screws 4|! maybe tightened a little more than usual to provide amore effective seal. With this type of construction the cylindricalbushing ll rotates with 3! given a ground or polished finish. Shaft 3bmaybe held against endwise movement in any conventional manner, forinstance, by .a suitably located thrust bearing I or the like which, ifdesired, may be fastened directly to shaft 3b and rotate therewith. Theseal is accomplished in the following manner. A ringmember 3| providedwith set screws 32- is mounted on shaft extending sleeve member 35. Awasher 38 which may be constructed of various materials, and

preferably of hardened or stainless steel, is pro-' vided with a groundor polished face adapted to abut and tightly fit end 30 of tubularmember 23. This washer is preferably provided with outwardly projectinglugs 81 (Figure 7) which loosely fit grooves 38 in the end of sleevemember 35. This construction causes washer 86 to rotate in unison withring member 3| so that the rotary bearing surface of the seal will be onend 3|] of tubular member 23. Between washer 35 and ring member ii .ismounted a washer 39, and intermediate of washers 38 and 39 is aresilient cylindrical bushing II which may be of soft rubber, neoprene,"or the like. Screws 40 threadedly engage and pass through ring member 3|in axial direction, and the point end of said screws bear against theouter face of washer 39. with the seal mechanism 'assembled andcylindrical bushing ii in place, the tightening of screws I moves washer39 to the right as viewed in Figure 5, and compresses cyl-, indricalbushing H which is held on all four sides, thus causing this bushing togrip shaft 3!: and form a tight seal therewith as well as with the othersurfaces which it contacts. At the same time, washer 38 is pressedagainst outer end 30 of tubular member 23 to form the rotary contactsurface of the seal. The degree of tightthe shaft, while in theconstructions shown in Figures 1 and 2, the cylindrical bushing I4 isshown as held in fixed position. The sleeve 3! (Figure 5) acts as anouter retainer for cylindrical bushing l4, while in Figures 1 and 2 thisbushing is illustrated as free from this outward expansion restraininginfluence. The invention, however, is not limited to that specificconstruction since it is obvious that the cylindrical bushing I could bemade slightly larger in outer diameter so as to fully flt recess II orIla without varying from the principles of the present invention.

Other modes of applying the principle of my invention may be employedinstead of those explained, change being made as regards the mechanismherein disclosed, provided the means stated by the following claim orthe equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

In a seal to prevent escape of fluid along a shaft, the combination witha rotary'shaft and a stationary member through which said shaft extends,of a pair of continuous and full face metal seal members in runningcontact with each other, a sleeve type member cooperating with one ofsaid seal members in manner permittlnz endwise movement of the latterrelative vto said sleeve type member, an elongated substantiallycylindrical, continuous, 'and resilient bushing substantially concentricwith said sleeve type member and in contact with the back face of saidseal member cooperating with said sleeve type member, means forsupporting the opposite end of said resilient bushing so as to placesame under endwise compression and force said pair of metal seal membersinto a running contactseal with each other, even under moderate gyra--tion or end play of said shaft, and corrugationson the faces of saidseal member and supporting means which are in contact with the ends ofsaid resilient bushing to facilitate elimination of lay-pass leakage offluid, said corrugations being substantially concentric, with saidshaft. ROBERT B. YAUCH.

